Field of Invention
The present invention relates to a video information hiding technology, particularly involves a 3D-HEVC depth video information hiding method based on single-depth intra mode.
Description of Related Arts
With the development of the network and communication technology, information security is more and more important and pressing. Information hiding technology is an effective way to deal with this problem. 3D video became more and more popular in movie industry and for entertainment application so the 3D extension of HEVC (High Efficiency Video Coding) standard namely 3D-HEVC standard attracts much attention. Depth video is an important part of 3D video which is used for drawing color virtual viewpoint and not for direct view. Partial depth distortion of depth video will not cause the distortion of color virtual viewpoint, which makes the depth video information hiding technology under 3D-HEVC standard has significant meaning.
Conventionally, the video information hiding algorithm mainly based on single-viewpoint video coding standard. The information hiding technology based on single-viewpoint HEVC standard achieved preliminary development with the wide application of HEVC standard. For example, the HEVC intra prediction mode related information hiding algorithm brought up by WANG et al. which needs re-encoding using the modified prediction mode and thus has high complexity; Tew et al. proposed an algorithm in which the unit splitting depends on the embedded information and the parity modulation of quantized non-zero DCT coefficient is taken into consideration, as a result, the whole performance of the algorism gets improved. However, the 3D video information hiding algorithms are few. A blind watermarking algorithm of 3D video based on quantization index modulation brought up by Yang embeds the watermarking information in the DCT coefficients of the depth video. Since the algorithm embeds watermarking information in the image domain of the depth video, the embedded information may be lost after compressing. The conventional 3D video information hiding algorithm for compression domain is based on and extends from single-viewpoint H.264 standard, such as a reversible multi-view video information hiding algorithm brought up by SONG which hides the information in motion vectors of coding block in b4 frame using inner product. The method achieves good imperceptibility and is reversible. The 3D-HEVC has a significant better compression performance than H.264, which is capable of encoding a higher definition video sequence. So it is necessary to carry out research on 3D video information hiding algorithm based on 3D-HEVC coding standard. Since there are many smooth regions and edge regions in depth video, the performance of the information hiding algorithm is not able to achieve predicted effects if simply applies the information hiding technology of the color video on the depth video. In 3D-HEVC, there is a “single-depth intra mode” which is designed for the smooth region of the depth video while 3D video coding standard extended from single-viewpoint H.264 is not equipped, this provides a new way to embed the hidden information in depth video.